close

Вход

Забыли?

вход по аккаунту

?

Gas-Inclusion Crystals of Tetra-tert-butyltetrahedrane and Its Deformation Density.

код для вставкиСкачать
for Fe3(C0)9 complexes containing two four-electron p3ligands.
Et
N
Et\
(CO),Fe-
Et
LNTNi+
-Fe(C0)3
\
I
Fe
(CO),
N
Et
1
2
The green complex 1 and the red complex 2 were characterized by elemental analyses and by their EI-mass spectra. Representatives of both types of complex have already
been prepared via other routes, and their molecular structures are known."] The IR data of 1 and 2 establish their
relation to them; the N M R data, which reveal the diastereotopy of the CH2 groups in 1 and the equivalence of the
ethyl groups in 2 lend support to the assignment.I6l
The mechanism of the transformation of 1 into 2 can be
explained in terms of the arguments presented by Shaprey
and HofSmann['' for the transformation of a p3-RZC2ligand into two ~ ~ - R C - l i g a n d s . Accordingly,
[~l
the R,N,ligand in 1 could slide to an edge of the metal triangle that
is not parallel to the N N bond. The new Fe-N bonds
would then b e formed via a transition state such as 3 with
synchronous opening of the Fe-Fe and N-N bonds.
However, from our experience with the ready fragmentation of cluster frameworks[81a mechanism involving reactive fragments also cannot be ruled out.
Nuel, R. Mathieu, J. Organomer. Chem. 307 (1986) C 5 ; and references
cited therein.
[3] R. L. De, D. Wolters, H. Vahrenkamp, 2. Naturforsch. 8 4 1 (1986) 283;
W. Bernhardt, H. Vahrenkamp, Organometallics 5 (1986) 2388.
141 H. Fleckner, F. W. Grevels, D. Hess, J . Am. Chem. Soc. 106 (1984)
2027.
(51 R. J. Doedens, lnorg. Chem. 8 (1969) 570; H. Kisch, C. Kriiger, A. Trautwein, Z . Naturforsch. 8 3 6 (1981) 205; W. Clegg, G. M. Sheldrick, D.
Stalke, S . Bhaduri, H. K. Khwaja, Acta Crysrallogr. Sect. C40 (1984)
2045.
161 IR (hexane [cm-'I): 1 : V=2079 w, 2033 vs, 1992 s, 1978 sh, 1970 w; 2 :
V = 2053 S, 2036 S, 1999 VS, 1970 w, 1962 VW.- 'H-NMR (CDCI,, TMS
int.): 1 : 6=4.18 and 3.21 ( J = 14.0, 7.0 Hz; CHZ), 1.60 (J=7.0 Hz, CH,);
2 : 6=3.47 (J=7.5 Hz; CHI), 1.37 (5=7.5 Hz; CH3).
[7] For a modification of these arguments cf. B. Eaton, J. M. OConnor, K.
P. C. Vollhardt, Organometallics 5 (1986) 394.
[8] H. Vahrenkamp, Adu. Organomet. Chem. 22 (1983) 169.
191 M. Dekker, G. Knox, Chem. Commun. 1967, 1243; M. M. Bagga, W. T.
Flannigan, G. R. Knox, P. L. Pauson, J . Chem. Sac. C1969, 1534; E. W.
Abel, T. Blackmore, R. J. Whitley, Inorg. Nucl. Chem. Lett. 10 (1974)
941; P. Mastropasqua, A. Riemer, H. Kisch, C. Kriiger, J . Organomet.
Chem. 148 (1978) C40; M. I. Bruce, M. G. Humphrey, 0. B. Shawkataly, M. R. Snow, E. R. T. Tiekink, ibrd. 315 (1986) C51.
[lo] R. Millini, H. Kisch, Z . Naturjorsch. 8 4 0 (1985) 187, and previous publications in this series.
Gas-Inclusion Crystals of Tetra-tert-butyltetrahedrane
and Its Deformation Density**
By Hermann Irngartinger, * Reiner Jahn. Giinther Maier,
and RolfEmrich
Having elucidated the structure of tetra-tert-butyltetrahedrane, 1,"' we decided to determine the deformation
density in 1 by low-temperature X-ray diffraction at 103 K
according to the X-X method.121We found thereby that the
hexagonaI crystals grown at 213 K had entrapped nitrogen
t
N
+
2
The cleavage of N = N bonds in, e.g. azides, azo compounds etc., in reactions with carbonylmetal compounds is
not unusual and leads to numerous types of products.[g1
Obviously, the transformation 1 -+ 2 can be seen as the elementary step in such reactions. Moreover, analogous
cleavages with chemical reagents should correspond to the
spontaneous thermal N-N cleavage in 1. We therefore expect that, besides the chemistry developed by Kisch['ol for
the organic molecular moiety of iron complexes of cyclic
azoalkanes, also a new derivative chemistry at the nitrogen
via complexes such as 1 and 2 and their dinuclear analogues can be elaborated.
Received: December I f , 1986;
revised: February 2, 1987 [Z 2006 IEI
German version: Angew. Chem. 99 (1987) 353
molecules at lattice sites. The solvent used for the crystallization had been purged with a stream of nitrogen beforehand in order to remove dissolved oxygen. The nitrogen
molecules were found to be disordered at the centers of the
threefold rotoinversion axes. To avoid disorder effects during the determination of the deformation density we grew
argon-clathrates at 213 K.[31 These gas-inclusion crystals
are held together exclusively by van-der- Waals forces.
Such clathrates were previously only known in crystals
with hydrogen bonds.[41Two sorts of octahedral holes are
present in the ratio 1 :2 in the hexagonal closest packed
structure of 1 (Fig. 1). The octahedral holes, each of which
is surrounded by only one of the four tert-butyl groups per
tetrahedrane molecule, entrap the gas molecules o r atoms.
The remaining holes are too small. In the packing diagram
(Fig. 1) the positions of the argon atoms are marked by
[*] Prof. Dr. H. Irngartinger, Dr. R. Jahn
[I] M. Moskovits: Metal Clusters. Wiley, New York 1986; B. C. Gates, L.
Guczi, H. Knozinger: Metal Clusters in Catalysis. Elsevier, Amsterdam
I QR6
121 Cf. A. D. Clauss, J. R. Shapley, C. N. Wilker, R. Hoffmann, OrganometaNics 3 (1984) 619; E. Boyar, A. J. Deeming, S. E. Kabir, J. Chem. Soc.
Chem. Commun. 1986, 577; K. P. C. Vollhardt, M. Wolfgruber, Angew.
Chem. 98 (1986) 919; Angew. Chem. Int. Ed. Engl. 25 (1986) 929; D.
356
0 VCH Verlagsgesellscha~mbH. 0-6940 Weinheim. 1987
Organisch-chemisches Institut der Universitat
Im Neuenheimer Feld 270, D-6900 Heidelberg 1 (FRG)
Prof. Dr. G. Maier, Dr. R. Emrich
Institut fur Organische Chemie der Universitat
Heinrich-Buff-Ring 58, D-6300 Giessen 1 (FRG)
[**I This work was supported by the Deutsche Forschungsgemeinschaft and
the Fonds der Chemischen Industrie.
0570-0833/87/0404-0356 3! 02.50/0
Angew. Chem. Int. Ed. Engl. 26 (1987) No. 4
0.06 e A-' vs. 0.04 e A-' in general positions). The density
maxima of the tetrahedral bonds are located 0.37 A outwards from the bond axis. Therefore these bonds are bent
by 26". The tetrahedrane bond is thus one of the most
strongly bent C-C bonds.151Theoretical calculations[61give
bends of the same order of magnitude. An arc over the
density maximum between two tetrahedrane C-atoms is
1.7 A long, whereas the distance between the atoms is
1.497 A. The density maxima of the bonds between the tetrahedrane C-atoms and the quarternary C-atoms of the
tert-butyl groups (Fig. 2) lie exactly on the connecting lines
between the atoms. This is also the case for the Cquar,-Cmethyl
bonds of the tert-butyl groups.
Received: December 15, 1986;
revised: January 22, 1987 [Z 201 1 IE]
German version: Angew. Chem. 99 (1987) 356
Fig. I . Packing diagram of the argon inclusion crystal of 1 (projection along
c); argon atoms marked by circles.
circles. The occupancy in the crystal used was 26%. On
heating the crystals in the mother liquor to a temperature
above 220 K under the microscope gas bubbles were observed escaping from the crystals and the solution. The
crystals became cloudy; without the supporting gas-inclusions the lattice is destroyed. On the basis of low-temperature data, the two mirror-image torsional disorder sites of
the tert-butyl groups, which extended into the holes occupied by argon atoms, could be refined separately. The torsional angle between the two disorder sites was found to
be 26 '. The thermal parameters yielded a torsional vibration of 9" for the tert-butyl groups, which can be explained
in terms of dynamic libration or static disorder. In comparison to the measurement at 213 KI'l the bond lengths were
essentially free of effects produced by the non-spherical
electron density distribution in the bonds,l2]because of the
refinement with reflections of high order.13]
In all cases the deformation densities were calculated in
sections (Fig. 2) along a tetrahedral bond and through the
,
1A
,
,
1A
~
[I] H. Irngartinger, A. Goldmann, R. Jahn, M. Nixdorf, H. Rodewald, G.
Maier, K.-D. Malsch, R. Emrich, Angew. Chem. 96 (1984) 967; Angew.
Chem. Int. Ed. Engl. 23 (1984) 993.
12) P. Coppens, Angew. Chem. 8 9 (1977) 33; Angew. Chem. Int. Ed. Engl. 16
(1977) 32.
[3] Crystallographic data of the argon-clathrate of 1 at 103 K : crystal growth
at 213 K from ethyl acetate, saturated with argon: C20H36+0.086Ar;
a = 15.732(2), c = 13.923(1) A; hexagonal space group P6,/m; Z = 6 ;
p,,,,=0.94 x lo6 g/rn3; three independent data sets with a total number of
12515 intensities (Enraf-Nonius CAD4 diffrfctometer, M o ~ radiation,
#~
graphite monochromator): sin(Q/A)=O-0.60 A - ' ; 1109 observed reflections (1>3o(f)) for calculation of the deformation densities; sin(B/d)
637 observed reflections (1>2.5u(l))for the refinement
=0.65-1.15 k':
with reflections of high order (C anisotropic, full matrix); R=0.06. The
positional and the isotropic thermal parameters of the H atoms have been
determined within the low-order refinement (sin 0/A< 0.65 A - I;
R =0.04). Bond lengths ( T = tetrahedron): CT-CT 1.497, CT-CTUdr,
1.498,
Cqunr,-CmclhYl
1.529 A; standard deviations: 0.003, 0.004, 0.006 A. Further
details of the crystal structure are available from the Fachinformationszentrurn Energie, Physik, Mathematik GmbH, D-7514 Eggenstein-Leopoldshafen 2 (FRG), on quoting the depository number CSD-52295, the
names of the authors, and the journal citation.
[4] J. L. Atwood, J. E. D. Davies, D. D. MacNicol: Inclusion Compounds.
Academic Press, Bristol (England) 1984.
[5] H. Irngartinger, A. Goldmann, Angew. Chem. 94 (1982) 786; Angew.
Chem. Int. Ed. Engl. 21 (1982) 169.
I61 a) T. Loerzer, R. Machinek, W. Liittke, L. H. Franz, K.-D. Malsch, G .
Maier, Angew. Chem. 95 (1983) 914; Angew. Chem. I n t . Ed. Engl. 22
(1983) 878; b) K. KovaEeviC, Z . B. MaksiC, J . Org Chem. 39 (1974) 539.
Trimethylenemethane Complexes of Cr, Mo, and W
by Novel Methylenation of Allenes
with Carbene Complexes;
Cyclopentanes by I3 + 21 Cycloaddition of
Trimethylenemethane Complexes to Allenes**
By RudolfAumann* and Jiirgen Uphoff
The development of versatile C3 building blocks for the
synthesis of functionalized cyclopentanes by [3 21 cycloaddition continues to be a challenge for many synthetic
chemists. In addition to ionic C, components,"] organometallic C, building blocks exhibiting 1 ,)-dipolar
have been used so far.
We recently described the synthesis of cyclopentanes by
or arylcarbene
[3 + 1 11 cycloaddition of ~inylcarbene[~'
complexes (as C3 components) and two equivalents of
methyl isocyanide (as C I component^).^^^
+
+
Fig. 2. Deformation densities of 1 [3]. All sections along a bond and perpendicular to the opposite bond of the tetrahedron. The atoms and midpoints of
the bonds marked in the formulas with circles all lie in the plane of the section. Contour interval 0.05 e A-3.
midpoint of the opposite tetrahedral bond. Sections with
maxima in special positions (mirror planes) have been ignored because of the high standard deviation (o@)=
Angew. Chem. I n t . Ed. Engl. 26 (1987) No. 4
[*I Prof. Dr. R. Aumann, Ing. (grad.) J. Uphoff
Organisch-chemisches Institut der Universitat
Orleans-Ring 23, D-4400 Miinster (FRG)
[**I Organic Syntheses with Transition-Metal Complexes, Part 22. This work
was supported by the Fonds der Chemischen 1ndustrie.-Part 21: 141.
0 VCH Verlagsgesellschaft mbH. 0 - 6 9 4 0 Weinheim, 1987
0570-0833/87/0404-0357 $ 02.50/0
357
Документ
Категория
Без категории
Просмотров
2
Размер файла
241 Кб
Теги
deformation, crystals, butyltetrahedrane, inclusion, tetra, tert, gas, density
1/--страниц
Пожаловаться на содержимое документа